Kids get their traits from their parents by getting an allele of each trait from each parent.
How are traits inherited?
Each trait is represented by a gene and each gene is represented by two alleles.
The two alleles for each gene are donated by each of the two parents in a union.
For example, let us say the eye color gene is represented by the allele A (a).
One parent is AA while the other is aa.
A child will inherit eye color by getting one A allele from one parent and the other allele (a) from the other parent. Thus, the child will be Aa.
More on inheritance of traits can be found here: